Quartz crystal wrist watch

ABSTRACT

A quartz crystal wrist watch wherein means are provided for removably mounting along the periphery of the watch the battery power source, the oscillator and associated circuitry and an electro-mechanical converter. The electro-mechanical converter is provided with a rotor coupled to the gear train of the watch positioned in the central portion thereof. The oscillator and associated circuitry are removably mounted in said watch by means of a resin case adapted to carry said oscillator and associated circuitry.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of my copending applicationSer. No. 166,501, filed July 27, 1971 now U.S. Pat. No. 3,800,523.

BACKGROUND OF THE INVENTION

This invention relates to quartz crystal wrist watches and to thephysical structure thereof. Quartz crystal wrist watches are generallyprovided with a battery power source, a crystal oscillator which servesas a time standard and associated circuitry for converting the output ofthe oscillator to the desired driving signal, an electro-mechanicalconverter responsive to said driving signal such as a pulse motor andindexing mechanism, and the drive train of the watch.

These components must be mounted in a watch so as to provide a compactthin structure. Further, although it is more convenience to mount thesecomponents in a square watch, there is a larger demand for round wristwatches, thereby complicating the mounting of these structures into awatch case. Thus, the battery power source requires a substantialportion of the space of the wrist watch, and being generally round inshape, occupies a greater space than its volume would otherwiseindicate. Further, if other components are mounted above or below thebattery, the thickness of the watch would be substantially increased.

The oscillator and associated circuitry includes the crystal oscillatorgenerally mounted in a vacuum in a hermetic sealed case provided with ashield cap and external lead terminal, an oscillation circuit, a fineadjusted mechanism for adjusting the frequency of the oscillator, atemperature compensating element, a divider circuit for dividing thefrequency of the output of the crystal oscillator, and a driving circuitfor the electromechanical converter. If these components are separatelymounted, assembly and repair of the watch becomes difficult andexpensive. Further, the method of mounting these components must avoidfrequency changes due to stray capacitance and external shock.

By the compact assembly approach of the invention, the foregoingdifficulties are solved.

SUMMARY OF THE INVENTION

Generally speaking, in accordance with the invention, the components ofa quartz crystal wrist watch are mounted so that the battery powersource, the oscillator and associated circuitry and theelectro-mechanical converter are mounted on the periphery of the watch,with the rotor of said electromechanical converter being positionedcentrally of said watch for cooperative engagement with the drive trainof said watch, also located in the central portion thereof. Theoscillator and associated circuitry are removably mounted on said watchby means of a resin case provided with grooves therein for receiving thevarious components.

Accordingly, the object of the invention is to provide a compactelectronic crystal wrist watch having a round configuration.

Another object of the invention is to provide an electronic quartzcrystal wrist watch incorporating a tuning fork crystal oscillator asthe time standard having a frequency of more than 16 kHz, oscillationand divider circuits including MOS transistors, a driving circuitincluding integrated circuits, and a pulse motor serving as anelectro-mechanical converter.

A further object of the invention is to provide a quartz crystal wristwatch wherein the various components thereof are readily connectedtogether for ease in after sale service and assembly, and wherein thecrystal oscillator and the associated circuitry thereof are removablymounted as a unit.

Still another object of the invention is to provide a quartz crystalwrist watch having a time standard oscillator not affected by theenvironment, such as external disturbances due to shock or ambient straycapacitance.

Still other objects and advantages of the invention will in part beobvious and will in part be apparent from the specification.

The invention accordingly comprises the features of construction,combinations of elements, and arrangement of parts which will beexemplified in the constructions hereinafter set forth, and the scope ofthe invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the invention, reference is had to thefollowing description taken in connection with the accompanyingdrawings, in which:

FIG. 1 is a circuit diagram of a quartz crystal wrist watch according tothe invention;

FIG. 2 is a fragmentary plan view of the quartz crystal wrist watchaccording to the invention showing in particular the crystal oscillatorand circuitry associated therewith according to the invention;

FIG. 3 is a cross-sectional view of a resin case for receiving said timestandard oscillator and associated circuitry;

FIG. 4 is a cross-sectional view of the resin case of FIG. 3 having saidtime standard oscillator and associated circuitry mounted therein;

FIG. 5 is a full plan view of the quartz crystal wrist watch accordingto the invention;

FIG. 6 is a plan view of a quartz crystal wrist watch showing thestepping motor mechanism and associated portion of the drive trainconstructed in accordance with the instant inventor; and

FIG. 7 is a cross-sectional view of the stepping mechanism depicted inFIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, wherein an equivalent circuit diagram of thetime standard oscillator and associated circuitry of the watch accordingto the invention is depicted, crystal oscillator 1 is shown coupled toan oscillation circuit 2, in part through a stepped variable condenser 3for adjusting the frequency of the oscillator and a temperaturecompensating element 4. A resin case for receiving the oscillator andits associated circuitry is shown schematically by dashed line 5, saidassociated circuitry including a divider circuit 6 for reducing thefrequency of the output signal of the oscillator and a driving circuit 7for driving the motor or other electromechanical converter.

Referring now to FIG. 2, the time standard oscillator and associatedcircuitry is shown mounted on a resin case 8 which may be formed, forexample, from an eleastic resin having thermosetting properties, whichresin case is in turn mounted in the quartz crystal wrist watchaccording to the invention. The time standard crystal oscillator ismounted within a cylindrical crystal oscillator casing 9a. The crystaloscillator is mounted within said casing on a stem, and is provided withthree external lead terminals 10. Casing 9a is evacuated, and is sealedhermetically.

The crystal oscillator utilized as time standard may be a tuning forkcrystal oscillator having a frequency of more than 16 kHz. An alternatetype of oscillator is a leaf spring oscillator, which is advantageousfor mass production, but requires 23 mm in length where a frequency of16 kHz is required, and where resistance to outside shocks is required.A leaf spring oscillator of less than 23 mm in length is substantiallyaffected by the suspension wire and may not be used as a time standardsource in a wrist watch. The length of the leaf spring oscillator iseven further increased to about 28 mm when it is suspended within ahermetically sealed case by a shock resistant mounting. For theforegoing reasons, the leaf spring oscillator is not particularlyadapted for use in compact and round wrist watch movements, andaccordingly, the tuning fork oscillator is preferred. Said tuning forkoscillator may be only 13 mm in length, and may be specially mounted andsealed hermetically within a cylindrical metal case of only 16 mm inlength.

The crystal oscillator casing 9a is provided with a cap 9b on theexternal lead terminal portion thereof in order to minimize the effectof stray capacitance between said external lead terminals and otherportions of the circuitry. The lead wires pass through windows inportions of said cap, but the crystal oscillator is shielded. Thetemperature compensating element 11 is formed of BaTiO₃ and is wired toother lead elements by a terminal plate 12.

Also mounted on resin case 8 is a stepped variable condenser for fineadjustment of frequency of said oscillator. Said condenser consists of agroup of condensers formed on a glass substrate 13 by vacuumevaporation. A contact spring 14 is mounted on said resin plate by meansof screw 15 above said glass substrate. The separate condensersdeposited on substrate 13 can be selectively added to or removed fromthe circuit to determine the total capacitance thereof by means of agroup of pins 16 which selectively engage one of the fingers of contactspring 14 to bring said finger into engagement with the correspondingcapacitor on the substrate. In other words, the fingers of contactspring 14 may be selectively brought into and out of engagement with thecapacitors on substrate 13 by inserting or removing pin 16.

The oscillation circuit, divider circuit and driving circuit, formedfrom MOS transistor components and integrated circuits, are mounted onthe opposed side of resin case 8 opposite substrate 13. Said componentsare retained within the resin case by means of an epoxy resin whichprotects said components from outside influences such as moisture. Saidelectronic circuits include a 15-stage flip-flop divider circuit fordividing the frequency of the output of the oscillator circuit and areset circuit. Both the oscillation and divider circuits may be formedof hybrid integrated circuits, but if MOS circuits are utilized, boththe oscillation and divider circuits can be incorporated in about a 2 mmsquare space. Even with the use of epoxy resins, by using MOS circuits,the space required for the oscillation and divider circuitry can bereduced by from one-half to one-third, as compared with the spacerequired by conventional type of circuits using only integratedcircuits. The lead terminals of the electric circuits mounted below theresin case 8 are electrically connected to the components above saidresin case by means of screws and pin connectors, as well as a group oflead terminals 18 preferably formed as thin plates. The top surface ofthe resin case may be enclosed by a metal holder 19 which serves as ashield plate for the capacitors on substrate 13, and as a retentiondevice for contact spring 15, pin 16 and crystal oscillator 9a.

Referring now to FIGS. 3 and 4, we see that the top surface of resincase 8 is formed with a channel 20 for receiving the crystal oscillator9, a channel 21 for receiving the stepped variable condenser substrate13, and a channel 23 for receiving the temperature compensating element11. The back of resin case 8 is provided with a channel 22 for receivingthe oscillation and divider circuits 17a, the driving circuit 17b whichis coupled to an electro-mechanical converter, silicon 17c forprotecting the circuits, and an epoxy resin 17d for retaining saidcomponents together. The channel 21 for receiving the stepped variablecondenser substrate and channel 22 for receiving the electric circuitsare positioned in overlapping relation on opposed sides of the resincase.

Accordingly, it is seen that the components of the crystal oscillatorand its associated circuitry are all mounted on resin case 8 for removalfrom and mounting in the quartz crystal watch case according to theinvention as a unit. The structure is extremely compact, occupying fromabout one-third to about one-fifth of the volume of the available spacein the watch. The foregoing arrangement greatly enhances both theinitial manufacture and the aftersale maintenance of the watch, sincethe entire time standard oscillator assembly can be replaced as a unit,and can be worked on outside of the watch. The structure is particularlyshielded to prevent the adverse effect of stray capacitance on theoscillator. Further, the crystal oscillator is firmly mounted within theresin case which is elastic, and therefore assists in shock resistance.

Referring now to FIG. 5, the quartz crystal watch depicted therein isprovided with a stem 31 disposed at the position of 12 O'clock, on around plate 32. A battery 33 is mounted on said plate at about 3O'clock. As noted above, the battery is round but is positioned at theperiphery of the watch. A negative pulse terminal plate 34 connects thebattery 33 to the oscillator circuitry which is mounted on resin case35. Said resin case is similar to the resin case 8 described above, inthat it supports all of the components of the oscillator and associatedcircuitry for removable mounting on plate 32. The crystal oscillatorcasing 36 containing the crystal oscillator is disposed in a channel onthe top surface of resin case 35. Fine adjustment of the frequency ofthe oscillator is provided by stepped condenser 37 similar in structureto the condenser 13, 14, 15 and 16 of FIGS. 2 and 4. Also mounted on theresin case is the temperature compensating device 38. The electroniccircuitry 39 is fixed on the opposed side of resin case 35 opposite thestepped condenser. The input and output terminals of said electroniccircuitry include electrical signal terminal 40a for applying thedriving signal to the pulse motor which serves as the electromechanicalconverter. These terminals all extend from one of the electroniccircuitry, namely the side on which said pulse motor is positioned. Theremaining terminals all extend from the opposed side of the electroniccircuitry. Specifically, terminals 40c are connected to the crystaloscillator, terminal 40d is connected to the negative pulse terminal 34of the battery, and terminal 40e is a reset terminal. The latterterminals are all positioned on the side of the electronic circuitryadjacent the battery. The output and input terminals of the tuning forkcrystal oscillator 41 are also disposed on the battery side of theoscillator case 36, in order to simplify the terminal connection withthe circuitry. Leads 42 are provided for connecting the steppedcondenser and temperature compensating device. Coupled to the electricalcircuitry 39 by leads 40a is the electro-mechanical converter 43a whichconverts the electrical output signal from said circuit into rotarymovement of the gear train of the watch. Said electromechanicalconverter includes a coil 13a formed from copper wire having 2.5/100φmm, which wire is wound in about 15,000 turns on a coil core formed ofmagnetic material. Coil 43a defines the driving coil of the pulse motorand is substantially cylindrical in shape. The output signal from saidcircuit consists of an alternating pulse train, one pulse of which isapplied to said driving coil each second. The magnetomotive forcegenerated in the coil is applied to stators 43b and 43c to rotate arotor 44 in predetermined angular increments. The rotor 44 may be madeof Pt CO material and is provided with six poles formed alternately asnorth and south poles.

The above described pulse motor is utilized in place of the conventionalpallet-fork escapement as an electro-mechanical converter, since saidpallet-fork escaptement occupies too large an area, and would precludethe provision of a round compact wrist watch. Thus, the pallet-forkescapement has an outer diameter of about 5˜7φmm, while the outsidediameter of the pulse motor is only about 3φmm. However, the cylindricalshape of the driving coil 43a precludes the mounting of any componentsabove or below said coil, where a thin wrist watch is desired.Accordingly, said driving coil is positioned on the periphery of thewatch according to the invention.

Rotor 44 is rotated by the magnetomotive force and its rotating energyis transmitted to a fourth wheel 45 of the watch gear train, which inturn in operatively coupled to the gear train third wheel and centerwheel for driving same. A second hand jumper 46 is coupled to fourthwheel 45 for indexing the position of the second hand. A regulatinglever 17 for the operation of said second hand is also positioned in thecentral region of the watch, one end of said regulating lever beingengaged with stem 31, the other end of said regulating lever beingengaged with the end of jumper 46 for manipulating said jumper.

The quartz crystal wrist watch according to the invention consists of aplurality of components arranged on a round plate in such manner thatthe stem is favorably disposed near the 12 O'clock position, the batteryis disposed near the 3 O'clock position, the time standard oscillatorand associated circuitry are formed as a unit and positioned adjacentthe battery, and the driving coil of the pulse motor is disposed betweenthe time standard oscillator and the stem. Said battery, time standardoscillator and associated circuitry and pulse motor driving coil arepositioned along the periphery of said round plate. The regulatingmechanism, along with the drive train of the watch are positioned in thecentral region of the watch, whereby overlapping relation between thelarger components is avoided.

Reference is now made to FIGS. 6 and 7 wherein a stepping motor assemblyis provided enabling the thickness of the electronic timepiece depictedin FIG. 5 to be further diminished, like reference numerals beingutilized to depict like elements. Specifically, the stepping motormechanism, generally indicated at 60 in FIG. 6, and the gear trainmechanism, generally indicated at 62 in FIG. 7 allow both suchassemblies to be contained within the plate of the wrist watch therebyproviding for a thinner wrist watch mechanism. This is achieved byplacing the coil and rotor in the same plane in the manner hereinafterdiscussed.

It is noted that in electro-mechanical converters such as steppingmotors, a driving coil is normally wound about the stator and a rotor isdisposed inside the coil and is rotated by the stator coil. Suchconfiguration results in a unitary motor which is easily disengageablefrom the timepiece. However, such motors cause sharp increases in thethickness of the timepiece thereby rendering same not suited for thin,small sized round wrist watches.

Accordingly, as is particularly depicted in FIGS. 6 and 7, the coil 43ais wound about a coil core 56 which is coupled to yokes 43b and 43c,which yokes act as stators and are disposed in the same plane as rotor44. The rotor 44 is mounted on shaft 44a, which is supported by geartrain bridge 58 which bridge also supports the shafts of gear trainmembers including fourth wheel 45 and third wheel 54. Thus, because therotor shaft 44a and the coil 43a have about the same height, thethickness of the timepiece can be reduced to the order of the coil.Furthermore, by merely removing bridge 58, it is easy to remove therotor 44 and the entire gear train if it is desired to fix same. Thestator defined by coil core 56 and yokes 43b and 43c can likewise beseparately removed from plates 32. Accordingly, by providing yokes forthe stator and a bridge member as depicted in FIGS. 6 and 7, a thinnerround electromechanical wrist watch is provided.

The foregoing arrangement provides for simplified terminal connectionsand for a round, particularly flat watch movement. Further, three majorcomponents of the watch, specifically the battery power source, theoscillator and associated circuitry and the mechanical components of thewatch, may be readily separated, with the function of each block beingseparately adjustable. This feature, which permits the removal ofcomponents by merely removing selected screws, is particularlyadvantageous to after-sales service. Further, this arrangement is alsoparticularly adapted for mass production.

It will thus be seen that the objects set forth above, and those madeapparent from the preceding description, are efficiently attained and,since certain changes may be made in the above constructions withoutdeparting from the spirit and scope of the invention, it is intendedthat all matter contained in the above description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of language, might be said to fall therebetween.

What is claimed is:
 1. In a quartz crystal wrist watch, the improvementwhich comprises a quartz crystal time standard oscillator means forproviding a high frequency time standard signal, a dividing circuit forproviding low frequency time .[.signals.]. .Iadd.signal .Iaddend.inresponse to said time standard .[.signals.]. .Iadd.signal .Iaddend.fromsaid time standard oscillator means, a stepping motor being driven inresponse to the low frequency timing signals applied by said dividingcircuit, said stepping motor including a driving coil, a yoke formed ofhigh permeability materials disposed through said driving coil andformed with spaced ends defining poles lying in the same plane as saiddriving coil and a rotor disposed in the gap between said poles andlying in the same plane as said driving coil; battery power meanscoupled to said time standard oscillator means, dividing circuit anddriving coil for energizing same; a support plate; said driving coil,battery power means and quartz crystal time standard oscillator meansbeing supported on peripheral regions of said plate out of overlappingrelation with each other and with said rotor; a bridge member; and agear train mechanically coupled to said rotor to be driven thereby, saidrotor and at least the portion of said gear train coupled thereto beingsupported by said bridge member and said plate at a central region ofsaid plate.
 2. A quartz crystal watch as claimed in claim 1, whereinsaid rotor is mounted on a shaft, said rotor shaft being substantiallythe same height as said coil.
 3. A quartz crystal watch as claimed inclaim 1, wherein said yoke and coil are removably mounted on said wristwatch for removal independent of said rotor. .Iadd.4. A quartz crystalwatch as claimed in claim 1, wherein said dividing circuit is formedfrom MOS transistors. .Iaddend. .Iadd.5. In a quartz crystal wristwatch, the improvement which comprises a quartz crystal time standardoscillator means for providing a high frequency time standard signal;battery power means coupled to said time standard oscillator means; adividing circuit for providing a low frequency time signal in responseto said time standard signal from said time standard oscillator means; astepping motor including a driving coil coupled to receive as an inputthereto said low frequency time signal, a stator magnetically coupled tosaid driving coil and a rotor formed of permanently magnetic materialand magnetically coupled to said stator, said rotor including amechanical output transmitting member; mechanical gearing coupled tosaid mechanical output transmitting member for driving by said rotor; abridge member; and a support plate, said rotor, driving coil and statorbeing arranged in a plane substantially parallel to the plane of saidsupport plate within the area defined by said support plate, saidmechanical gearing, mechanical output transmitting member and rotorbeing supported by said support plate and bridge member at a centralregion of said support plate, said battery power means and time standardoscillator means being located out of overlapping relation with eachother and with said driving coil, said driving coil and battery powermeans being supported on peripheral regions of said plate. .Iaddend..Iadd.6. A quartz crystal watch as claimed in claim 5, wherein saiddividing circuit is formed from MOS transistors..Iaddend.